Vehicle ignition switch

ABSTRACT

A vehicle ignition switch having a plunger which operates a gearbox locking device. The switch has a housing and the plunger, which is rotatable relative to the housing, extends from the housing and slidable relative thereto into and out of a locking position. The housing carries fixed contacts for selective engagement by movable contacts carried by the plunger upon rotary movement of the latter. A slot in the housing is engaged by a projection carried by the plunger so that, in order to rotate the plunger to a position in which the fixed contacts are not engaged by any of the movable contacts, the plunger must be slid into its locking position.

Unite States Patent Cardwell Nov. 6, 1973 [54] VEHICLE IGNITION SWITCH 2,046,831 7/1936 Lowe 200/44 X [75] Inventor: John William Cardwell, 8 Tatton St., 7 Colne, England Primary ExaminerHerman J. Hohauser [73] Assignee: Joseph Lucas (Industries) Limited, Atmmey john Holman et Birmingham, England [22] Filed: May 12, 1972 [57] ABSTRACT PP N05 252,744 A vehicle ignition switch having a plunger which operates a gearbox locking device. The switch has a housing [30] Foreign Application Priority Data and the plunger, which is rotatable relative to the hous- 12 1971 G {B 14 540/71 ing, extends from the housing and slidable relative dy ma n am thereto into and out of a locking position, The housing U 8 Cl 200/44 carries fixed contacts for selective engagement by mov- [51] In} .0 27/00 able Contacts carried y the p g p rotary move Fie'ld R 44 42 R ment of the latter. A slot in the housing is engaged by 200/16 a projection carried by the plunger so that, in order to rotate the plunger to a position in which the fixed con- References Cited tacts are not engaged by any of the movable contacts,

UNITED STATES PATENTS the plunger must be slid into its locking position.

3,145,700 8/1964 Root 200/44 X 2 Claims, 4 Drawing Figures PATENTEDHUI 6197s 3.770.816

SHEET 20F 2 VEHICLE IGNITION SWITCH This invention relates to a vehicle ignition switch which also provides an actuating element for a locking arrangement for a gearbox on the vehicle.

According to the invention, there is provided a vehicle ignition switch for actuating a locking arrangement for a vehicle gearbox, said switch comprising a housing, a plunger slidable and rotatable in the housing, said plunger being engageable at one position of its sliding travel with said locking arrangement to actuate the latter, means for biassing the plunger away from the said one position of its sliding travel, a plurality of fixed contacts carried by said housing, a plurality of movable contacts connected with the plunger for rotary movement relative to the fixed contacts, a co-operating projection and slot means on said plunger and housing whereby the said plunger can be moved to said one position of its sliding travel when said movable contacts are in predetermined positions relative to said fixed contacts.

An example of the presentinvention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section through a switch,

FIG. 2 is a section on line 2-2 in FIG. 1,

FIG. 3 shows diagrammatically the switch contact and terminal arrangement, and

FIG. 4 is a view of an associated gearbox locking arrangement.

The switch has a housing within which a plunger 11 is slidable and rotatable. Plunger 11 includes a barrel portion 12 which incorporates a known type of locking'mechanism operable by a vehicle ignition key. Plunger 11 also has a portion 13 of square section which is slidable within a contact carrier 14 which is rotatable with the plunger 11.

Housing 10 supports fixed terminals l5,l6,l7,18. Terminals 15,16 and 17 have associated fixed contact areas 19,20,21, respectively. Mounted on carrier 14, for rotation therewith, is a conductive washer-like member 22 from which three integral equi-spaced contact parts 23 radially extend. Member 22 is biassed so that contact parts 23 are urged axially towards fixed contact areas 19,20,21. Carrier 14 supports a springloaded ball 24 engageable with -co-operating detent means, not showing on housing 10 to arrest carrier 14 in three of four angular positions A,B,C,D, as shown in FIG. 3, position A of carrier 14 being shown in dotted outline.

Plunger 11 includes a portion 25 extending from housing 10 at the end thereof remote from barrel portion 12. A radial projection 26 on plunger 11 extends into an arcuate slot 27 within housing 10. Slot 27 includes a step 28 which is positioned so that plunger 11 must be moved downwards, as seen in FIG. 1, in order to be rotated to bring carrier 14 to position A. Plunger 11 is biassed upwards by a spring 29. Upward movement of plunger 1 1 is restrained by engagement of projection 26 with the upper face of slot 27 and also by en gagement of a circlip 30 on plunger 11 with a plate 44 forming part of housing 10.

The switch is associated with a gear-box arrangment, as for example that described in our co-pending Application No. 4884/71 and shown somewhat diagrammatically in FIG. 4. Three selector rods 31,32,33 are slidable in a part 34 which has a bore 35. Rods 31,32 have transverse through bores 36,37 respectively, and rod 33 has a recess 38, bores 36,37 and recess 38 being aligned with each other and with bore 36 when a given gear (conveniently neutral) is selected. Plungers 39,40 are respectively slidable in bores 36,37 and balls 41,42,43 are slidable in bore 35.

Plunger 11 is engageable with ball 41 to urge the latter towards plunger 39 by cam action as shown, or alternatively by direct axial movement as shown in '1 1a in FIG. 4.

In use an electrical supply is connected to terminal 16, and terminals 15,17 and 18 are respectively connected to ignition, auxiliary and starter circuits for the vehicle. With the switch in position A, all terminals are isolated and plunger 11 is depressed to lock rods 31,32,33 in the neutral position. In position B, the auxiliary circuits are supplied, in position C auxiliary and ignition circuits are supplied, and in position D the starter and ignition circuits are supplied. The switch is urged from position D towards position C by a torsion spring 45.

I claim:

1. A vehicle ignition switch for actuating a locking arrangement for a vehicle gearbox, said switch comprising a housing, a plunger slidable and rotatable in the housing, said plunger being engageable at one position of its sliding travel with said locking arrangement to actuate the latter, means for biassing the plunger away from the said one position of its sliding travel, a plurality of fixed contacts carried by said housing, a plurality of movable contacts connected with the plunger for rotary movement relative to the fixed contacts, a co-operating projection and slot means on said plunger and housing whereby the said plunger can be moved to said one position of its sliding travel when said movable contacts are in predetermined positions relative to said fixed contacts, and wherein the plunger has a portion of non-circular cross-section internally of movable contacts. 

1. A vehicle ignition switch for actuating a locking arrangement for a vehicle gearbox, said switch comprising a housing, a plunger slidable and rotatable in the housing, said plunger being engageable at one position of its sliding travel with said locking arrangement to actuate the latter, means for biassing the plunger away from the said one position of its sliding travel, a plurality of fixed contacts carried by said housing, a plurality of movable contacts connected with the plunger for rotary movement relative to the fixed contacts, a co-operating projection and slot means on said plunger and housing whereby the said plunger can be moved to said one position of its sliding travel when said movable contacts are in predetermined positions relative to said fixed contacts, and wherein the plunger has a portion of non-circular cross-section internally of the housing, a carrier supporting the movable contacts is mounted in the housing for rotary movement with the plunger, the plunger being slidable relative to the carrier.
 2. A switch as claimed in claim 1, wherein the slot is provided with a step therein in such a position that the plunger has to be moved to said one position of its sliding travel to attain a position in which the fixed contacts are not electrically connected with any of the movable contacts. 